Device for inhibiting the theft of pull-start internal combustion engines

ABSTRACT

A device for preventing the theft of pull-start internal combustion engine devices comprising a key-lock plug integrated into the hand-grip.

The present invention relates to a device for inhibiting the theft ofinternal combustion engines, for instance outboard engines, lawn mowerengines, chain-saw engines, and like engines of the kind in which oneend of a pull-cord is wound firmly around a rotatable magnet on theengine, or motor, and the other end of the cord is attached to a handle,wherein a pull on the cord causes the magnet to rotate and therewithgenerate an ignition spark in a spark plug or plugs.

Outboard motors are often theft-attractive objects and are often mountedon the boat solely by means of a manually manipulatable attachment. Thisapplies in particular to engines of up to 30 HP. it is a simple matterto detach engines of this kind from the boat to which they are fittedand install the engine on another boat. All that is required is toconnect the engine fuel feed to a fuel tank. The theft of such enginescan be prevented by bolting the engine securely to the boat, which willnormally prevent the theft of the engine itself. However, in cases suchas these it is not unusual for theboat to be stolen together with theengine attached. However, the theft of a boat and its engine, or motor,also requires the engine fuel feed to be connected to a fuel tank, inpeace and quiet, i.e. while undisturbed. Thefts of this nature may beeither planned or spontaneous, with the object of selling theengine/boat.

The inventor and other Applicants have come to the conclusion that thereis a need for a device which will at least inhibit unlawful activitiesin this regard, irrespective of the underlying purpose, andparticularly, but not exclusively, the theft of boat engines.

The object of the invention is not only to inhibit the actual theft, butalso to cause such damage to a stolen engine as to make it difficult tosell the engine, for instance, should the theft-inhibiting device besuccessfully overcome. Spontaneous thefts that are carried out for the"sake of fun" can be prevented more effectively, however.

The inventor also realizes that it must be possible to retail atheft-inhibiting device of this kind at a reasonable price, in order forthe device to gain popularity with potential customers.

These and other objects are achieved with a device of the kind definedin the introduction and having the characteristic features set forth inthe characterizing clause of the following main claim.

The invention will now be described in more detail with reference to anexemplifying embodiment of an inventive theft-inhibiting device and alsowith reference to the accompanying drawing, in which

FIG. 1 is a longitudinal section view of an inventive device;

FIG. 2 is a front view of the device shown in FIG. 1; and

FIG. 3 illustrates the components of an inventive device.

The theft-inhibiting device is intended for use with internal combustionengines, not shown. More particularly, but not exclusively, the deviceis intended for use with engines that are started with the aid of apull-cord whose one end is attached to a rotatable magnet means fittedto the engine. This technique is well known and will not be described orillustrated here.

An outboard engine, or motor, is always provided with an engine casingand an attachment plate 10 may be firmly mounted on one side of theengine casing (not shown). The mounting plate 10 includes a sleeve-likemember 11 which is welded firmly to the mounting plate 10 and supportedby strengthening means 12'. The mounting plate and the sleeve-likemember 11 connected thereto may be firmly mounted on the engine casingin a manner not shown. The end of the sleeve 11 distal from the mountingplate 10 has formed therein a circular groove 12. Alternatively, thisend of the sleeve 11 may be collared. In the former case, the opposingvertical walls 13 of the groove 12 each form an abutment or definingsurface. Only one forward abutment or defining surface is formed in thelatter case.

The reference numeral 14 identifies generally a handgrip which includesa cylindrical body 15 which is received loosely in the sleeve 11. Oneend of the cylindrical body 15 is provided with a small or relativelysmall opening 16 which opens into a larger space 17, this space beingaccessible from outside said member through an opening 18. As shown inFIG. 1, a pull-cord 19 is firmly connected to the body 15, and the space17 and the opening 18 have been provided so as to enable the pull-cord19 to be connected in the manner illustrated. The end of the cord 19located in the small opening 16 may conveniently be thickened so as tolie firmly in said opening.

The body 15 also includes a vertical bore 20 which opens at a distancefrom the opening 18 (at 21 in FIG. 3). This bore 20 has a semi-circularcross-sectional shape and functions to receive a locking member 22. Themanner in which the locking member 22 works and the purpose of saidmember will be described further on.

The handgrip 14 includes a forward part 23 which is connected to thebody 15, preferably integrally therewith, and which is located outsidethe sleeve 11 and intended to be handled by the operator. Thehandgrip-part 23 includes a lock plug 24 of conventional basicconstruction, the pin tumblers of which can be activated with the aid ofa conventional key 25.

The lock plug 24 is inserted through an opening 26 in the grip-part 23and extends towards the pull-cord 19. The free end, or inwardly pointingend of the lock plug 24, coacts with the locking device 22 which isrotatable together with the lock plug.

The inventive device functions in the following manner:

In one state of the device, the locking device 22, which can be movedtransversely to the longitudinal axis of the body 15, is generally flushwith the surface of said body (see FIG. 1). When the grip-part 23 ispulled in the direction of the arrow A, the device will functionnormally to start the engine. When the key 25 is inserted into the lockarrangement and turned through about 180°, subsequent rotation of thelock plug will cause the locking device 22 to enter the circular recess12 and prevent pulling of the handgrip-part 14.

As a further safeguard against unauthorized activity, the inventivedevice may be provided with a microswitch 27 so that when the enginestarting arrangement is locked in the afore-described way, themicroswitch will break the electric circuit to earth and therewith stopthe supply of current to the coil or magnet on the outboard engine. Thecurrent connection is re-established when the locking device 22 is in apassive state.

It will be obvious to the person skilled in this art that the lockingdevice 22 can be formed in different ways, one essential feature beingthat the locking device can be activated by turning the key 25.

I claim:
 1. A device for use with internal combustion engines which arestarted with the aid of a pull-cord having first and second ends wherethe first end is wound onto and connected to a rotatable magnet on theengine and the second end is firmly attached to a handgrip, wherein apull on the handgrip will cause the magnet to rotate and therewithgenerate an ignition spark in the spark plug or spark plugs,characterized by a cylindrical body (15) which is connected to thehandgrip (14) and guided for movement in a tubular guide (11); akey-operated lock plug (24) mounted within the handgrip (14); and alocking member (22) which cooperates with the lock plug (24), whereinrotation of the lock plug (24) entrains the locking member (22) andmoves said device from a first position in which the handgrip (14) canbe pulled out to a second position in which the handgrip (14) isprevented from being pulled out, or vice versa.
 2. A device according toclaim 1, characterized in that the cylindrical body (15) is connected toa handgrip-part (23) of the handgrip (14) and includes a bore (20) whichextends transversely to the longitudinal axis of the cylindrical body(15), wherein the locking member (22) is mounted in the bore (20) suchthat turning of the key (25) will result in limited vertical movement ofthe locking member (22).
 3. A device according to claim 2, characterizedin that the body (15) has an internal side surface which in the regionlying proximal to the handgrip part (23) includes a recess (13) in whichthe locking member (22) engages.
 4. A device according to claim 3,characterized in that the recess (13) is circular.
 5. A device accordingto claim 3, characterized in that the locking member (22) isspring-biased.
 6. A device according to claim 1, 2, 3, 4, or 5,characterized by a microswitch (27) which in the active locking positionof the locking member (22) functions to break the electric circuit toearth and therewith break the supply of electric current to the coil ormagnet.